<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
    <input type="text" v-model="num1">
    <input type="text" v-model="num2">
    <input type="button" value="加" @click="f(1)">
    <input type="button" value="减" @click="f(2)">
    <input type="button" value="乘" @click="f(3)">
    <input type="button" value="除" @click="f(4)">
    <div>
        结果:{{result}}
    </div>
</div>

<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<script>
    let v=new Vue({
        el:"body>div",
        data:{
            result:"未运算",
            num1:"",
            num2:""
        },
        methods:{
           f(x){
               switch (x) {
                   case 1:
                       v.result=v.num1*1+v.num2*1;
                       break;
                   case 2:
                       v.result=v.num1-v.num2;
                       break;
                   case 3:
                       v.result=v.num1*v.num2;
                       break;
                   case 4:
                       v.result=v.num1/v.num2;
                       break;
               }
           }
        }
    })

</script>
</body>
</html>